org.jbrain.qlink.db.DBUtils.java Source code

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Here is the source code for org.jbrain.qlink.db.DBUtils.java

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/*
   Copyright Jim Brain and Brain Innovations, 2005.
    
   This file is part of QLinkServer.
    
   QLinkServer is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
    
   QLinkServer is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with QLinkServer; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    
   @author Jim Brain
   Created on Sep 9, 2005
       
 */
package org.jbrain.qlink.db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.apache.log4j.Logger;
import org.apache.commons.configuration.Configuration;

import org.jbrain.qlink.QConfig;

public class DBUtils {
    private static Logger _log = Logger.getLogger(DBUtils.class);

    public static void init() throws Exception {
        try {
            if (QConfig.getInstance().getBoolean("qlink.db.use_google_driver")) {
                // If we're using the Google Cloud SQL JDBC driver, pulls it in.
                Class.forName("com.mysql.jdbc.GoogleDriver");
            } else {
                // Otherwise, uses the system default MySQL JDBC driver.
                Class.forName("com.mysql.jdbc.Driver").newInstance();
            }
        } catch (Exception e) {
            _log.fatal("Could not load MySQL JDBC driver", e);
        }
    }

    public static Connection getConnection() throws SQLException {
        Configuration config = QConfig.getInstance();
        try {
            String username = System.getenv("QLINK_DB_USERNAME");
            String password = System.getenv("QLINK_DB_PASSWORD");
            String jdbcUri = System.getenv("QLINK_DB_JDBC_URI");

            if (username == null) {
                username = config.getString("qlink.db.username");
            }

            if (password == null) {
                password = config.getString("qlink.db.password");
            }

            if (jdbcUri == null) {
                jdbcUri = config.getString("qlink.db.jdbc_uri");
            }

            // TODO move this userid and password somewhere else
            Connection conn = DriverManager.getConnection(jdbcUri, username, password);
            return conn;
        } catch (SQLException e) {
            _log.error("Could not get DB Connection", e);
            throw e;
        }
    }

    public static void close(Connection c) {
        if (c != null)
            try {
                c.close();
            } catch (SQLException e) {
            }
    }

    public static void close(Statement s) {
        if (s != null)
            try {
                s.close();
            } catch (SQLException e) {
            }
    }

    public static void close(ResultSet rs) {
        if (rs != null)
            try {
                rs.close();
            } catch (SQLException e) {
            }
    }

    public static int getNextID(int start, int type, int max) {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        String sql;

        try {
            conn = DBUtils.getConnection();
            stmt = conn.createStatement();
            _log.debug("Attempting to find next available message base ID after " + start);
            int orig_id = start;
            do {
                start++;
                if (start > max)
                    start = 0;
                sql = "SELECT reference_id from entry_types where reference_id=" + start;
                _log.debug(sql);
                rs = stmt.executeQuery(sql);
            } while (rs.next() && start != orig_id);
            try {
                rs.close();
            } catch (Exception e) {
            }
            if (start == orig_id) {
                // error
                _log.error("Cannot find ID <=" + max);
                return -1;
            } else {
                _log.debug("Creating new entry_types record");
                sql = "insert into entry_types (reference_id,entry_type,create_date,last_update) VALUES (" + start
                        + "," + type + ",now(),now())";
                _log.debug(sql);
                stmt.execute(sql);
                if (stmt.getUpdateCount() == 0) {
                    _log.error("Could not insert record into entry_types");
                    return -1;
                }
            }
            return start;
        } catch (SQLException e) {
            _log.error("SQL Exception", e);
            return -1;
        } finally {
            close(rs);
            close(stmt);
            close(conn);
        }
    }

}